Determination of quercetin and kaempferol in folium mori extract after hydrolysis by hydrochloric acid

To establish a method to determine the contents of quercetin and kaempferol in folium mori extract by HPLC,the flavones in folium mori extract were hydrolyted into quercetin and kaempferol with the mixed solution of methanol—hydrochloric acid.The contents of quercetin and kaempferol were determined by HPLC method,performed on Diamonsil C18 column with the mobile phase consisted of methanol-0.20% phosphoric acid solution(63∶37).The flow rate was 1.0 mL·min-1,the UV wavelength was set at 370 nm.The linear ranges of quercetin and kaempferol were 0.84-26.8 mg·L-1,0.44-14.2 mg·L-1,respectively.The average recoveries of quercetin and kaempferol were 101.3%,99.5%.The method was accurate,reliable and with good reappearance for the determination of quercetin and kaempferol in folium mori extract.